At least some known turbine engines, such as gas turbines and steam turbines, use axial entry buckets, i.e., rotor blades that are coupled to a rotor wheel by sliding the buckets generally parallel to the rotor axis into mating dovetail slots defined on the rotor wheel. Likewise, some known buckets include radial-inwardly projecting dovetails that mate in dovetail slots formed on the rotor wheel. The rotor wheel dovetail slots are circumferentially-spaced apart from each other about the periphery of the rotor wheel
The majority of last stage buckets are of significant length and weight. During low speed (turning gear) operation, the buckets have the ability to move within the rotor dovetails. This unwanted movement may cause significant wear on the buckets and/or the rotor dovetails of the axial or curved axial entry bucket designs. It may be desirable to have some movement to facilitate the assembly of the buckets, as the outer cover ends typically have interlocking features and also may have mid-span interlocking features. Moreover, the buckets must pass each other during assembly of the last bucket in the row assembly. Springs are traditionally used to keep the bucket loaded on the outer dovetail surfaces but such configurations may have operational limitations that are not desired.